Many internal surgical procedures require the removal of tissue as part of the surgical procedure. The removal of such tissue invariably results in severing multiple blood vessels leading to localized blood loss. Significant blood loss may comprise the patient's health by potentially leading to hypovolemic shock. Even minor blood loss may complicate the surgery by resulting in blood pooling into the surgical site, thereby obscuring the visibility of the tissue from the surgeons and surgical assistants. The problem of blood loss into the surgical site may be especially important in broad area surgeries, such as liver resection, in which multiple blood vessels may be severed during the procedure.
Typically, an electrosurgical cautery device is used to seal the blood vessels, thereby preventing blood loss. Such electrosurgical cautery devices may include bipolar devices that incorporate a pair of electrodes that are powered by RF (radiofrequency) energy to heat and cauterize the tissue and blood vessels. Direct application of the electrodes to the tissue may lead to unwanted effects such as localized tissue charring and fouling of the electrodes by charred tissue matter sticking to them.
A method to reduce charring and fouling may include introducing a saline fluid into the surgical site to irrigate the site. Alternatively, the saline fluid may be heated by the electrodes to form a steam to cauterize the tissue. In this manner, the tissue is not placed in direct contact with the electrodes and electrode fouling is prevented. Although a saline fluid may be used, any electrically conducting fluid (for example, an aqueous mixture containing ionic salts) may be used to promote steam-based cauterization. After the steam cauterizes the tissue by transferring its heat thereto, the steam may condense to water. The resulting water may be used to clear the surgical site of unwanted material such as the remnants of the cauterized tissue. An aspirator may be used to remove the mixture of water and tissue remnants. It may be difficult and inefficient for the surgeon to cauterize and aspirate the tissue especially if separate devices are required. Thus, a device incorporating the cauterization and aspiration functions is desirable.
The incorporation of both a saline source and an evacuation source for aspiration into a bipolar electrosurgical cautery instrument may be problematic. If the aspirator operates continuously, then the saline may not reside in contact with the electrodes long enough to be heated and form steam. If the saline source operates continuously, then excess saline may be delivered to the surgical site and obscure the area from the surgeon. It is possible to have a device with multiple actuators to allow the surgeon to selectively emit a fluid to be vaporized by the electrodes and evacuate the surgical site. However, such multiple actuators may be clumsy to use and lead to hand and finger fatigue during a long surgical procedure.
Therefore, it is desirable to have a device that permits a surgeon to effectively and efficiently provide steam cauterization and tissue mixture aspiration to a surgical site without requiring excessive manipulation of the surgical device.